使用jQuery设置HTML选择选项的问题(Issue on Setting HTML Select Option Using jQuery)

使用jQuery设置HTML选择选项的问题(Issue on Setting HTML Select Option Using jQuery)

我试图在此演示中动态更改列表选项中的选定项目，但它无法正常工作。

<select id="selItems" class="selectpicker"> <option>Select From List</option> <option>Mustard</option> <option>Ketchup</option> <option>Relish</option> </select> <p> <button id="setdefault" type="submit" class="btn">Set Default</button> <script> $("#setdefault").on("click", function () { $("#selItems option:eq(2)").attr("selected", "selected"); }); </script>

能不能让我知道我做错了什么？

I am trying to change selected item from the list options dynamically at This Demo but it is not working.

<select id="selItems" class="selectpicker"> <option>Select From List</option> <option>Mustard</option> <option>Ketchup</option> <option>Relish</option> </select> <p> <button id="setdefault" type="submit" class="btn">Set Default</button> <script> $("#setdefault").on("click", function () { $("#selItems option:eq(2)").attr("selected", "selected"); }); </script>

can you please let me know what I am doing wrong?

最满意答案

尝试使用prop而不是attr ：

 $("#setdefault").on("click", function () {
   $("#selItems option:eq(2)").prop("selected", true);
 }); 
  
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select id="selItems" class="selectpicker">
    <option>Select From List</option>
    <option>Mustard</option>
    <option>Ketchup</option>
    <option>Relish</option>
</select>
<p>
<button id="setdefault" type="submit" class="btn">Set Default</button> 
  
 
Try using prop instead of attr:
 
 
 
  
  
 $("#setdefault").on("click", function () {
   $("#selItems option:eq(2)").prop("selected", true);
 }); 
  
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<select id="selItems" class="selectpicker">
    <option>Select From List</option>
    <option>Mustard</option>
    <option>Ketchup</option>
    <option>Relish</option>
</select>
<p>
<button id="setdefault" type="submit" class="btn">Set Default</button>